Steam-engine



SARS PATENT F.

H. \V. DOPI, OF BUFFALO, NEW' YORK.

STEAM-ENGINE.

Specification of Letters Patent No. 27,355, dated March 6, 1860.

To all whom it may concern:

Be it known that I, I-I. V. DoPr, of Buffalo, in the county of Erie and State of New York, have invented certain new and use ful Improvements in Steam-Engines; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the annexed drawings and the letters of reference marked thereon.

The nature of my invention consists in providing the valve balance with a piston or packing, said valve balance being stationary, but so arranged that it may by the action of the steam be kept in contact with the valves. Also a variable cut off which consists of a cam groove to disconnect the valves from their respective motions, and also other devices, the peculiarities of which, will be hereinafter fully setforth.

To enable others skilled in the art to make and use my invention I will proceed to describe its construction and operation.

In the accompanying drawings Figure (l) is a side elevation. Fig. (2) is a sectional view of the steam chest or valve box, showing also the peculiar construction and arrangement of the valve balance, and valves. Fig. is a view of the sliding valves, which are provided with cylinders and pistons, for the purpose of cutting off steam. It will be observed that the three ligures, included in Fig. are really such as are required to show different positions of the same device. Fig. (et) shows the sliding` valves operated by means of two rods, in a manner which will be hereafter fully explained. Fig. (5) is a perspective of the rockshaft and rocking arm showing also the cut off and knock od toes. Fig. (6) is merely for the purpose of exhibiting a modification of Fig. (2) and therefore no reference will be had to it in the following description.

In Figs. (Q, 3 and 4L) (A A) represents two sliding valves.

(B) is a valve or steam balance, shown in Fig. (2).

(D) represents the steam chest or valve box. Said chest or box is provided with a circular hole in its side for the admission of the balance piston (C), as fully seen in Figs. (l) and The steam chest (D) also serves as cylinder for balance piston (E) represents a hole, or cylinder in the valves (A A) for the purpose of closing the valves, when they are disconnected from (K K). Said valves are also provided with ports, which run at right angles, with the hole (E), and opens into it, in order that the steam passing through the ports, may act upon the pistons in holes (E). It should be observed, that this hole (E) is represented only in one valve though they both are constructed precisely in the same manner.

rlhe valve balance (B) is constructed, or may be constructed, so that it will serve as a side pipe, through which the steam conducted into the cylinder. Said balance (B) is provided with packing, at the point marked (C).

(F) and (F) are two valve rods, which are attached to the valves (A A). Said rods, are so constructed, that the one, which is attached to valve nearest the hooks, is hollow, while the others must pass through it, as shown in Fig. (4). This is done to enable the two valves to work at different speeds.

(G G) represent two docks, which are se cured to the valve rods.

(2, Q) are two catchpins on docks (G G), the object of which will be more fully seen hereafter.

(H) represents a combined rocking valve gear, the motion of which is communicated to the valves (A A) by means of the hooks (K K).

(I I) represent two cross heads, which slide upon rock arm (H), and to which the two hooks are connected by means of a pin (Y).

(X X) represent two links, attached at one end to the cross heads, and at their other end to steady pins-as fully shown in Fig.

(I) represents a shaft which is provided with two grooves, which resemble a right and left screw. Said shaft is also provided with a straight groove.

As shown in Fig. (5), (P) is a rock arm by which the shaft receives motion from eccentric or any other device.

(O O) are two knock off toes, fastened on the shaft (I) by means of the right and left cam grooves. The obj ect of the straight groove already referred to, is to secure the rock arm. It will be observed that the shaft (I) is so arranged that it can be moved in and out of rock arm (P) and knock off toes (O O)-in order that it may accommodate itself to the stroke of the engine.

(L) represents a joint link as shown in Fig. (3) which is secured at one end to the valve (A) and at the other to the piston (M,) by means of a dock, marked (3). The object of this link is to regulate the stroke of the valves, when they are disconnected by means of the knock 0H toes, O O, which are fully represented in Figs. (l and 5). Said joint link (L) also guards against sudden concussions.

(N N) are two stationary guides, designed to guide the pistons (M M), and also for the purpose of stopping the pistons (M M), when the valves commence to open the steam ports, and enable the pistons (M M) to push the valves (A A) from itself, the moment they are disconnected, in order to cut 0E the steam.

The operation of my invention is as follows: The steam being let on from the throttle valve, passes into the valve box through the balance (B B) which is hollow as is seen. The object in making this balance hollow is to prevent too much pressure and consequent friction upon the valves. When the area of the port leading to the balance is the same as the area of the openings in the two valves, the pressure upon the valves will amount to nothing; but when the area of the port is larger than the sum of the other two areas, then there will be pressure upon the valves in proportion to the difference of the two areas. The steam passes through the balance and to the valves-one valve being open the steam rushes into the cylinders and acting upon the piston head forces it back. The steam may be cut off at one quarter, one half, or at full stroke, according as the rock oft' toes (O, O), are set when the piston has made its full stroke. The valve which has just been admitting steam moves back with a quick movement and opens the exhaust ports instantly. At the same time the valve at the other end of the box opens and admits the steam on the other side of the piston head, which brings it back again. As soon as it has made its full stroke, the exhaust port behind is opened instantly and the steam escapes as soon as it is admitted at the other end again, and thus the operation continues. It will be seen that the steam is admitted to the cylinder by the short motion of the valve gear, and that the exhausts are opened by the long motion of said gear-this being the case the exhaust ports are opened quicker than the steam ports.

In this engine the steam ports, as well as the exhaust ports, are opened and closed quicker than they are in the ordinary engine because I have two motions from the valve gear. It will be seen that when the steam is cut olf by the rock off toes (O O) the steam in the valve pressing against the valve and against the piston the valve is caused to slide upon said piston and close the opening through which the steam is admitted to the cylinder. The valve is prevented from going too far in one direction by means of the stationary guide (N) and in the other direction by means of the link (L). It appears then that by this arrangement the steam ports are opened and the exhaust ports are opened and closed by means of the hooks (K K), while the steam ports are closed by means of a pressure of steam itself against the valves and pistons (M M) after the valves are disconnected.

Having thus fully described my invention, what I claim and desire to secure by Letters Patent isl. The stationary valve balance (B) constructed as described, in combination with steam valves (A A) or their equivalents.

2. I claim sliding valves A) when the same are constructed and used in the manner and for the purpose set forth.

3. I claim the employment of link, crank or arm as shown by link (k), in combination with pistons (M M) and valves (A A) as constructed.

l. I claim the combined rocking valve gear, when the same shall be constructed substantially as and for the purpose set forth.

5. I claim the employment of cam groove around the shaft (I) in combination with hooks (K K).

Dated Buffalo May 20, 1858.

H. WILLIAM DOPP.

Witnesses,

I. STELLWAGEN, ALEX. MARTEN. 

